X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=fc3ecae4d87e5c56230aec04a8bb6aacbee50cc0;hp=e8809f149170c31ceeea0ff821cd2751932506df;hb=db322e6a63459bc3dfdf7fd537d42234b854fb76;hpb=9f94d2280110a1ba5eb9eb15b0756883037a817d diff --git a/src/search.cpp b/src/search.cpp index e8809f14..fc3ecae4 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -26,7 +26,6 @@ #include "book.h" #include "evaluate.h" -#include "history.h" #include "movegen.h" #include "movepick.h" #include "notation.h" @@ -87,7 +86,8 @@ namespace { TimeManager TimeMgr; int BestMoveChanges; Value DrawValue[COLOR_NB]; - History H; + History Hist; + Gains Gain; template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth); @@ -98,9 +98,9 @@ namespace { void id_loop(Position& pos); Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); - bool check_is_dangerous(Position& pos, Move move, Value futilityBase, Value beta); - bool allows_move(const Position& pos, Move first, Move second); - bool prevents_move(const Position& pos, Move first, Move second); + bool check_is_dangerous(const Position& pos, Move move, Value futilityBase, Value beta); + bool allows(const Position& pos, Move first, Move second); + bool refutes(const Position& pos, Move first, Move second); string uci_pv(const Position& pos, int depth, Value alpha, Value beta); struct Skill { @@ -182,7 +182,7 @@ void Search::think() { static PolyglotBook book; // Defined static to initialize the PRNG only once RootColor = RootPos.side_to_move(); - TimeMgr.init(Limits, RootPos.startpos_ply_counter(), RootColor); + TimeMgr.init(Limits, RootPos.game_ply(), RootColor); if (RootMoves.empty()) { @@ -229,22 +229,22 @@ void Search::think() { // Reset the threads, still sleeping: will be wake up at split time for (size_t i = 0; i < Threads.size(); i++) - Threads[i].maxPly = 0; + Threads[i]->maxPly = 0; Threads.sleepWhileIdle = Options["Use Sleeping Threads"]; // Set best timer interval to avoid lagging under time pressure. Timer is // used to check for remaining available thinking time. - Threads.timer_thread()->msec = + Threads.timer->msec = Limits.use_time_management() ? std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)) : Limits.nodes ? 2 * TimerResolution : 100; - Threads.timer_thread()->notify_one(); // Wake up the recurring timer + Threads.timer->notify_one(); // Wake up the recurring timer id_loop(RootPos); // Let's start searching ! - Threads.timer_thread()->msec = 0; // Stop the timer + Threads.timer->msec = 0; // Stop the timer Threads.sleepWhileIdle = true; // Send idle threads to sleep if (Options["Use Search Log"]) @@ -293,14 +293,14 @@ namespace { Stack ss[MAX_PLY_PLUS_2]; int depth, prevBestMoveChanges; Value bestValue, alpha, beta, delta; - bool bestMoveNeverChanged = true; memset(ss, 0, 4 * sizeof(Stack)); depth = BestMoveChanges = 0; bestValue = delta = -VALUE_INFINITE; ss->currentMove = MOVE_NULL; // Hack to skip update gains TT.new_search(); - H.clear(); + Hist.clear(); + Gain.clear(); PVSize = Options["MultiPV"]; Skill skill(Options["Skill Level"]); @@ -353,7 +353,7 @@ namespace { // we want to keep the same order for all the moves but the new // PV that goes to the front. Note that in case of MultiPV search // the already searched PV lines are preserved. - sort(RootMoves.begin() + PVIdx, RootMoves.end()); + std::stable_sort(RootMoves.begin() + PVIdx, RootMoves.end()); // Write PV back to transposition table in case the relevant // entries have been overwritten during the search. @@ -398,7 +398,8 @@ namespace { } // Sort the PV lines searched so far and update the GUI - sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1); + std::stable_sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1); + if (PVIdx + 1 == PVSize || Time::now() - SearchTime > 3000) sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; } @@ -414,10 +415,6 @@ namespace { << std::endl; } - // Filter out startup noise when monitoring best move stability - if (depth > 2 && BestMoveChanges) - bestMoveNeverChanged = false; - // Do we have found a "mate in x"? if ( Limits.mate && bestValue >= VALUE_MATE_IN_MAX_PLY @@ -443,8 +440,8 @@ namespace { if ( depth >= 12 && !stop && PVSize == 1 - && ( (bestMoveNeverChanged && pos.captured_piece_type()) - || Time::now() - SearchTime > (TimeMgr.available_time() * 40) / 100)) + && ( RootMoves.size() == 1 + || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100)) { Value rBeta = bestValue - 2 * PawnValueMg; (ss+1)->excludedMove = RootMoves[0].pv[0]; @@ -492,7 +489,7 @@ namespace { Move movesSearched[64]; StateInfo st; const TTEntry *tte; - SplitPoint* sp; + SplitPoint* splitPoint; Key posKey; Move ttMove, move, excludedMove, bestMove, threatMove; Depth ext, newDepth; @@ -509,15 +506,15 @@ namespace { if (SpNode) { - sp = ss->sp; - bestMove = sp->bestMove; - threatMove = sp->threatMove; - bestValue = sp->bestValue; + splitPoint = ss->splitPoint; + bestMove = splitPoint->bestMove; + threatMove = splitPoint->threatMove; + bestValue = splitPoint->bestValue; tte = NULL; ttMove = excludedMove = MOVE_NONE; ttValue = VALUE_NONE; - assert(sp->bestValue > -VALUE_INFINITE && sp->moveCount > 0); + assert(splitPoint->bestValue > -VALUE_INFINITE && splitPoint->moveCount > 0); goto split_point_start; } @@ -592,8 +589,8 @@ namespace { else if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = eval = tte->static_value()) == VALUE_NONE - ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE) + if ( (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE + ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) eval = ss->staticEval = evaluate(pos, ss->evalMargin); // Can ttValue be used as a better position evaluation? @@ -618,7 +615,7 @@ namespace { && type_of(move) == NORMAL) { Square to = to_sq(move); - H.update_gain(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); + Gain.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); } // Step 6. Razoring (is omitted in PV nodes) @@ -705,7 +702,7 @@ namespace { if ( depth < 5 * ONE_PLY && (ss-1)->reduction && threatMove != MOVE_NONE - && allows_move(pos, (ss-1)->currentMove, threatMove)) + && allows(pos, (ss-1)->currentMove, threatMove)) return beta - 1; } } @@ -728,7 +725,7 @@ namespace { assert((ss-1)->currentMove != MOVE_NONE); assert((ss-1)->currentMove != MOVE_NULL); - MovePicker mp(pos, ttMove, H, pos.captured_piece_type()); + MovePicker mp(pos, ttMove, Hist, pos.captured_piece_type()); CheckInfo ci(pos); while ((move = mp.next_move()) != MOVE_NONE) @@ -760,7 +757,7 @@ namespace { split_point_start: // At split points actual search starts from here - MovePicker mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); + MovePicker mp(pos, ttMove, depth, Hist, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc singularExtensionNode = !RootNode @@ -792,8 +789,8 @@ split_point_start: // At split points actual search starts from here if (!pos.pl_move_is_legal(move, ci.pinned)) continue; - moveCount = ++sp->moveCount; - sp->mutex.unlock(); + moveCount = ++splitPoint->moveCount; + splitPoint->mutex.unlock(); } else moveCount++; @@ -855,21 +852,19 @@ split_point_start: // At split points actual search starts from here newDepth = depth - ONE_PLY + ext; // Step 13. Futility pruning (is omitted in PV nodes) - if ( !PvNode - && !captureOrPromotion + if ( !captureOrPromotion && !inCheck && !dangerous - && move != ttMove - && (bestValue > VALUE_MATED_IN_MAX_PLY || ( bestValue == -VALUE_INFINITE - && alpha > VALUE_MATED_IN_MAX_PLY))) + && move != ttMove) { // Move count based pruning - if ( depth < 16 * ONE_PLY + if ( !PvNode + && depth < 16 * ONE_PLY && moveCount >= FutilityMoveCounts[depth] - && (!threatMove || !prevents_move(pos, move, threatMove))) + && (!threatMove || !refutes(pos, move, threatMove))) { if (SpNode) - sp->mutex.lock(); + splitPoint->mutex.lock(); continue; } @@ -879,12 +874,12 @@ split_point_start: // At split points actual search starts from here // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_moved(move), to_sq(move)); + + Gain[pos.piece_moved(move)][to_sq(move)]; - if (futilityValue < beta) + if (!PvNode && futilityValue < beta) { if (SpNode) - sp->mutex.lock(); + splitPoint->mutex.lock(); continue; } @@ -894,7 +889,7 @@ split_point_start: // At split points actual search starts from here && pos.see_sign(move) < 0) { if (SpNode) - sp->mutex.lock(); + splitPoint->mutex.lock(); continue; } @@ -921,12 +916,14 @@ split_point_start: // At split points actual search starts from here && !pvMove && !captureOrPromotion && !dangerous - && ss->killers[0] != move - && ss->killers[1] != move) + && move != ttMove + && move != ss->killers[0] + && move != ss->killers[1]) { ss->reduction = reduction(depth, moveCount); Depth d = std::max(newDepth - ss->reduction, ONE_PLY); - alpha = SpNode ? sp->alpha : alpha; + if (SpNode) + alpha = splitPoint->alpha; value = -search(pos, ss+1, -(alpha+1), -alpha, d); @@ -939,7 +936,9 @@ split_point_start: // At split points actual search starts from here // Step 16. Full depth search, when LMR is skipped or fails high if (doFullDepthSearch) { - alpha = SpNode ? sp->alpha : alpha; + if (SpNode) + alpha = splitPoint->alpha; + value = newDepth < ONE_PLY ? givesCheck ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) : -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) @@ -962,9 +961,9 @@ split_point_start: // At split points actual search starts from here // Step 18. Check for new best move if (SpNode) { - sp->mutex.lock(); - bestValue = sp->bestValue; - alpha = sp->alpha; + splitPoint->mutex.lock(); + bestValue = splitPoint->bestValue; + alpha = splitPoint->alpha; } // Finished searching the move. If Signals.stop is true, the search @@ -999,20 +998,20 @@ split_point_start: // At split points actual search starts from here if (value > bestValue) { - bestValue = SpNode ? sp->bestValue = value : value; + bestValue = SpNode ? splitPoint->bestValue = value : value; if (value > alpha) { - bestMove = SpNode ? sp->bestMove = move : move; + bestMove = SpNode ? splitPoint->bestMove = move : move; if (PvNode && value < beta) // Update alpha! Always alpha < beta - alpha = SpNode ? sp->alpha = value : value; + alpha = SpNode ? splitPoint->alpha = value : value; else { assert(value >= beta); // Fail high if (SpNode) - sp->cutoff = true; + splitPoint->cutoff = true; break; } @@ -1022,13 +1021,13 @@ split_point_start: // At split points actual search starts from here // Step 19. Check for splitting the search if ( !SpNode && depth >= Threads.minimumSplitDepth - && Threads.slave_available(thisThread) + && Threads.available_slave(thisThread) && thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD) { assert(bestValue < beta); - bestValue = Threads.split(pos, ss, alpha, beta, bestValue, &bestMove, - depth, threatMove, moveCount, mp, NT); + thisThread->split(pos, ss, alpha, beta, &bestValue, &bestMove, + depth, threatMove, moveCount, &mp, NT); if (bestValue >= beta) break; } @@ -1071,13 +1070,13 @@ split_point_start: // At split points actual search starts from here // Increase history value of the cut-off move Value bonus = Value(int(depth) * int(depth)); - H.add(pos.piece_moved(bestMove), to_sq(bestMove), bonus); + Hist.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); // Decrease history of all the other played non-capture moves for (int i = 0; i < playedMoveCount - 1; i++) { Move m = movesSearched[i]; - H.add(pos.piece_moved(m), to_sq(m), -bonus); + Hist.update(pos.piece_moved(m), to_sq(m), -bonus); } } } @@ -1161,8 +1160,8 @@ split_point_start: // At split points actual search starts from here if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = bestValue = tte->static_value()) == VALUE_NONE - ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE) + if ( (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE + ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); } else @@ -1189,7 +1188,7 @@ split_point_start: // At split points actual search starts from here // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will // be generated. - MovePicker mp(pos, ttMove, depth, H, to_sq((ss-1)->currentMove)); + MovePicker mp(pos, ttMove, depth, Hist, to_sq((ss-1)->currentMove)); CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs @@ -1332,7 +1331,7 @@ split_point_start: // At split points actual search starts from here // check_is_dangerous() tests if a checking move can be pruned in qsearch() - bool check_is_dangerous(Position& pos, Move move, Value futilityBase, Value beta) + bool check_is_dangerous(const Position& pos, Move move, Value futilityBase, Value beta) { Piece pc = pos.piece_moved(move); Square from = from_sq(move); @@ -1366,12 +1365,12 @@ split_point_start: // At split points actual search starts from here } - // allows_move() tests whether the move at previous ply (first) somehow makes a - // second move possible, for instance if the moving piece is the same in both - // moves. Normally the second move is the threat move (the best move returned + // allows() tests whether the 'first' move at previous ply somehow makes the + // 'second' move possible, for instance if the moving piece is the same in + // both moves. Normally the second move is the threat (the best move returned // from a null search that fails low). - bool allows_move(const Position& pos, Move first, Move second) { + bool allows(const Position& pos, Move first, Move second) { assert(is_ok(first)); assert(is_ok(second)); @@ -1407,12 +1406,11 @@ split_point_start: // At split points actual search starts from here } - // prevents_move() tests whether a move (first) is able to defend against an - // opponent's move (second). In this case will not be pruned. Normally the - // second move is the threat move (the best move returned from a null search - // that fails low). + // refutes() tests whether a 'first' move is able to defend against a 'second' + // opponent's move. In this case will not be pruned. Normally the second move + // is the threat (the best move returned from a null search that fails low). - bool prevents_move(const Position& pos, Move first, Move second) { + bool refutes(const Position& pos, Move first, Move second) { assert(is_ok(first)); assert(is_ok(second)); @@ -1511,8 +1509,8 @@ split_point_start: // At split points actual search starts from here int selDepth = 0; for (size_t i = 0; i < Threads.size(); i++) - if (Threads[i].maxPly > selDepth) - selDepth = Threads[i].maxPly; + if (Threads[i]->maxPly > selDepth) + selDepth = Threads[i]->maxPly; for (size_t i = 0; i < uciPVSize; i++) { @@ -1612,13 +1610,11 @@ void Thread::idle_loop() { // Pointer 'this_sp' is not null only if we are called from split(), and not // at the thread creation. So it means we are the split point's master. - const SplitPoint* this_sp = splitPointsSize ? activeSplitPoint : NULL; + SplitPoint* this_sp = splitPointsSize ? activeSplitPoint : NULL; - assert(!this_sp || (this_sp->master == this && searching)); + assert(!this_sp || (this_sp->masterThread == this && searching)); - // If this thread is the master of a split point and all slaves have finished - // their work at this split point, return from the idle loop. - while (!this_sp || this_sp->slavesMask) + while (true) { // If we are not searching, wait for a condition to be signaled instead of // wasting CPU time polling for work. @@ -1666,13 +1662,13 @@ void Thread::idle_loop() { Position pos(*sp->pos, this); memcpy(ss, sp->ss - 1, 4 * sizeof(Stack)); - (ss+1)->sp = sp; + (ss+1)->splitPoint = sp; sp->mutex.lock(); - assert(sp->slavesPositions[idx] == NULL); + assert(activePosition == NULL); - sp->slavesPositions[idx] = &pos; + activePosition = &pos; switch (sp->nodeType) { case Root: @@ -1691,18 +1687,18 @@ void Thread::idle_loop() { assert(searching); searching = false; - sp->slavesPositions[idx] = NULL; + activePosition = NULL; sp->slavesMask &= ~(1ULL << idx); sp->nodes += pos.nodes_searched(); // Wake up master thread so to allow it to return from the idle loop // in case we are the last slave of the split point. if ( Threads.sleepWhileIdle - && this != sp->master + && this != sp->masterThread && !sp->slavesMask) { - assert(!sp->master->searching); - sp->master->notify_one(); + assert(!sp->masterThread->searching); + sp->masterThread->notify_one(); } // After releasing the lock we cannot access anymore any SplitPoint @@ -1711,6 +1707,17 @@ void Thread::idle_loop() { // unsafe because if we are exiting there is a chance are already freed. sp->mutex.unlock(); } + + // If this thread is the master of a split point and all slaves have finished + // their work at this split point, return from the idle loop. + if (this_sp && !this_sp->slavesMask) + { + this_sp->mutex.lock(); + bool finished = !this_sp->slavesMask; // Retest under lock protection + this_sp->mutex.unlock(); + if (finished) + return; + } } } @@ -1740,11 +1747,11 @@ void check_time() { nodes = RootPos.nodes_searched(); // Loop across all split points and sum accumulated SplitPoint nodes plus - // all the currently active slaves positions. + // all the currently active positions nodes. for (size_t i = 0; i < Threads.size(); i++) - for (int j = 0; j < Threads[i].splitPointsSize; j++) + for (int j = 0; j < Threads[i]->splitPointsSize; j++) { - SplitPoint& sp = Threads[i].splitPoints[j]; + SplitPoint& sp = Threads[i]->splitPoints[j]; sp.mutex.lock(); @@ -1752,8 +1759,9 @@ void check_time() { Bitboard sm = sp.slavesMask; while (sm) { - Position* pos = sp.slavesPositions[pop_lsb(&sm)]; - nodes += pos ? pos->nodes_searched() : 0; + Position* pos = Threads[pop_lsb(&sm)]->activePosition; + if (pos) + nodes += pos->nodes_searched(); } sp.mutex.unlock();